Radio tuning indicator



. 5, 1939. w. J. SCHNELL RADIO TUNING INDICATOR 4 Sheets-Sheet 1 Filed May 15, 1937 5, 1939. w. J. SCHNELL RADIO TUNING INDICATOR Filed May 15, 1937 4 Sheets-Sheet 2 dbl/aw 50/7/2610 @ozl 777002 w. J. SCHNELL 2,182,572 RADIO TUNING INDICATOR Filed May 15, 1937 4 Sheets$heet 3 im- 20 W i: g: t t t l t w. J. SCHNELL I 2,182,572 RADIO TUNING INDICATOR Filed May 15. 1937 '4 Sheets-Sheet 4 Patented Dec. 5, 1939 UNITED STATES tATENT ()FFiCE 2,182,572 RADIO TUNING INDICATOR William J .Schnell, Berwyn, Ill., assignor to Electrical Research Laboratories Inc., Chicago, 111., a corporation of Illinois Application May 15, 1937, Serial No. 142,863

12 Claims. (Cl. 25020) This invention relates to a radio tuning infor indicatingthe tuned condition of the receiver; dicator and adjusting device. to provide automatically operable means for An object of the invention is to provide, in a silencing the receiver during the tuning operaradio tuning indicator, simplified and inexpensive tion, which silencing means is rendered inopermeans to indicate the proper tuning position of ative by the position-indicating means. 5 the receiver for any of a desired number of Other and further objects of this invention broadcast stations. will become apparent from the following de- Another object is to provide a simple, accurate tailed description of one illustrative embodiment and inexpensive fast-operating tuning control for of the invention when considered with the acradio receivers. companying drawings wherein: 10

A further object of the invention is the pro- Fig. 1 is a face view of a portion of a radio sion of compact and efficient means operable receiver embodying the invention; in synchronism with the tuning device to indicate Fig. 2 is a schematic illustration of the tuning the tuned condition of the receiver. indicator and silencing circuits; It is another object of applicants invention to Fig. 3 is a vertical section taken along the line provide means operable in synchronism with the 3-3 of Fig. l; tuning control and co-operating with fixed means Fig. 4 is a vertical section at right angles to carrying indicia representative of the various Fig. 3 taken on the line t--i of Fig. 3; broadcasting stations to indicate the station to Fig. 5 is an exploded perspective view of the go which the receiver is tuned. dial assembly;

A further object of the invention is to provide Fig. 6 is a fragmentary horizontal section taken a simplified means for silencing the receiver duralong the line 6-6 of Fig. 3; ing the tuning operation. Figs. 7, 8 and 9 are perspective views of cer- Another object of the invention is to provide, tain elements of the mechanism; in a radio receiver having fixed means to indicate Figs. 10 to 13 are perspective views illustrating 25 the position to which the tuning control should one form of marking device embodied in apbe adjusted to tune the receiver to a desired staplicants invention;

tion, a circuit for silencing the receiver during Figs, 14, 15 and 16 are perspective views of a the tuning operation, which circuit is operable modified form of marking device, and

by said indicating means to restore the receiver Figs. 17 to 20 are perspective views of another 30 to normal condition when the desired station has modified form of marking device. been properly tuned. A tuning device of one form of applicants in- A further object is to provide a rugged but invention comprises a supporting plate i mounted expensive means for luminously indicating the on the inner side of the front face or panei 2 of tuned condition of the receiver, which means is a radio receiver. On the front face 3 or" the 35 automatically operable upon the tuning of the plate I there is mounted a ring 4 which fits closely receiver. within an opening provided in the panel 2 and has Another object of applicants invention is to an inwardly projecting annular flange 5 for atprovide, in a radio receiver, a luminous tuning taching the ring to the supporting plate. A indicator, a plurality of station indicating marksecond ring member 8 of channel cross-section is 40 ing devices, and means co-operating with said mounted in the ring 5, the inner flange l of the tuning indicator and operable by said devices to ring 6 being extended into frictional engageenergize said tuning indicator when the receiver ment with the ring i and the outer surfaces being becomes tuned to a station indicated by any one finished to provide a pleasing appearance. A of said marking devices. third ring or cover 8 is mounted on the ring I by 4 Still further objects of applicants invention hinge pintles I0 and II and pins H, the pins 12 are to provide a radio receiver capable of both being readily removable to permit complete rerapid and slow tuning; to provide in such a removal of the cover or its swinging to either side. ceiver, simplified means which indicates by call Spring strips 13 are secured to the annular flange letters as well as by frequency or wave length the 5 of the ring 4 within said ring, and these spring 50 proper tuning position of the receiver for the destrips bear against the cover ring 8 to prevent sired one of a number of broadcast stations, which vibration of the same. means is readily replaceable and adjustable at The face 3 of the supporting plate I is prothe will of the user; to provide tuning indicating vided with upper and lower semi-circular aper- :means operable by said position-indicating means tures l4 and I5 registering with each other, and 55 annular openings or slots l6, i! cut from the bottom portion of the face 3 concentric to the semi-circular aperture 55. A transparent or translucent shield l3 and a dial plate I9 are secured to the back of the supporting plate I by rivets (Fig. 3) which pass through aligned openings in the annular flange 5 of the ring 4, the supporting plate I, the shield l8 and the dial plate H3. The shield l8 and dial plate l9 are provided with semi-circular upper and lower portions mating with the apertures 64 and i5 in the supporting plate l. The dial plate it is made of opaque material, or other material rendered opaque, and carries indicia representative of various broadcast scales etched in, or left transparent, to permit light to pass therethrough from the rear of the dial plate.

The dial plate it is provided with arcuate cutouts 2i, 2.? and 23, which co-operate with a segmental band indicator 2 for indicating the band to which the receiver is responsive. This band indicator segment 24 is provided with transparent arcuate portions 25, 26 and 21 which are differently colored and inscribed with characteristic indicia representative of one of the bands and are adapted to be selectively positioned behind one of the cut-outs 2i, 22 and 23.

The tuning condenser 28 is mounted in the usual manner on the receiver chassis 29 and on 1 the front face of the chassis is mounted a U- shaped bracket 3t (Fig. 3) in which is journalled a tuning shaft 3!. The tuning shaft 3i is connected by a common coupling 32 to the shaft of the tuning condenser 28 and to the hub of i a pulley the pulley 33 being driven in the usual manner by a cable 34 passing over an axle 35 journalled in the bracket 30 and operable by a control knob 36. It will be apparent that the control knob 36 has a step-down ratio of movement with respect to the shaft 3! and therefore provides a slow or fine tuning adjustment.

The tuning shaft 3! extends forwardly from the bracket 30 and passes through the segmental band indicator 24, the dial plate 19, the shield l8 and the supporting plate I, and receives on its outer end a double-ended pointer 31 adapted to co-operate with the dial plate is to indicate the position of the tuning condenser. A bracket 38 is secured by a bolt 39 to the rear side of the plate 6 and by a bolt 40 to the upper end of the bracket 30 to support the same. The band indicator 24 is secured by a bracket or arm M to a disc 42 loosely mounted on the shaft 3i adjacent the bracket 3t and the disc 42 is operated, through a link 43 and a crank 44, by a manually operable knob 45 passing through the panel 2 and secured to the crank 44. The knob 45 also controls, in the usual manner, the selective contacts by which the various bands of the receiver are selected.

A fast operating control lever 46 is secured at its upper end to a collar 4? which is secured to the shaft 3i by a set screw 48. In addition to the vertical portion 49, to which the collar 4'! is secured, the control lever 46 is provided with a horizontal portion 56.! extending forwardly from the portion lfithrough the slot I! of the plate i; a vertical portion 5! extending downwardly from the portion 5i and passing through an arcuate slot 52 in the outer flange of the ring '6; a horizontal portion 53 extending forwardly from the vertical portion 5i beyond the plane of the ring 6 and a vertical portion 54 extending downwardly from the portion 53 and carrying an operating knob 55.

A lamp socket 56 is mounted by an insulating bushing 57 in an aperture 58 formed in the portion of the lever 46 adjacent the vertical portion 49. The lamp socket 56 is provided with contacts 59 and 60 insulated from each other and connected internally to the usual lamp-engaging contacts. A pilot lamp 6| of ordinary type, is inserted in the socket 5'6 and a shield 62 having a slot 83 is adapted to be inserted over the lamp 6! and direct the rays of light therefrom forwardly through a translucent strip 64 secured along its lower edge to the face plate 3 of the support I. The translucent strip 64 extends across and registers with the aperture IS in the support I.

A lug 65 is struck from the vertical portion 48 of the lever 46 and to this lug is attached an insulating strip 66 which carries a pair of spring contact strips 61 and 68. A wire or lead 69 extends frorn one of the lamp contacts (59 and 60) to the contact E53 and the contact 61 is connected by a lead H3, in a manner later to be described to certain of the grid biasing and silencing circuits of the radio receiver. The other contact for the lamp 6| is connected by a lead H to one side of the grounded secondary winding of a power supply transformer 12 (Fig. 2).

Between the semi-circular aperture 15 and the arcuate slot it of the supporting plate I there is left a semi-circular annular strip or guide 513 and this strip is adapted to detachably receive a plurality of annularly spaced clips 14. As shown in Figs. 10-13, the clip 14 may comprise a channel member 15, the rear flange T6 of which is provided with an upstanding con tact lug Ti and the front flange 18 of which forms one wall of a housing 79. The channel member 15 is made of a resilient conductive material for the purpose of frictionally retaining the clip 14 on the strip 13 and for completing a connection between the contacts 61 and 68 carried by the operating lever 46. The housing 19 is adapted to receive a bent strip of any transparent material possessing the necessary stiffness and resiliency for the purpose. A tab Bl of transparent or translucent material is adapted to receive suitable inscription representing the call letters and/or wave length or frequency of a desired broadcasting station. The tab 8i, after being inscribed, is inserted between the folds of the bent strip or cover 80, and the cover fit is provided with a convex-concave lip 82 at its upper edge to register with a similar concave-convex lip 83 formed on the front flange '13 of the channel member 15; these two lips interengaging to resiliently lock the tab 8| and the cover 89 to the clip 74.

In the form shown in Figs. 14 to 16, the clip M comprises a channel member 84 similar to the channel member "iii and this member 84 has a rear flange 85 provided with an upstanding contact lug at similar to the contact lug 1?. The front flange 87 of the channel member 84 is bent forwardly and then downwardly to form, between the flange 8i and the downwardly bent portion 88, a channel for receiving and frictionally retaining the bent strip or cover 30 and the tab 8|.

The clip F4 shown in Figs. 17 to 20 comprises a channel member 89 similar to the channel members 84 and 75, and the rear flange of this channel has an upstanding contact lug 90 similar to the contact lugs i1 and 86. To the forward flange ill of the channel member 89 there is secured a cap bolt Q2 and a box-like member 93,

which is open at the back and bottom, is pro- 75"" vided with an aperture in one wall for admitting passage of the bolt 92 therethrough. A transparent cover strip 94 similar to the cover strip 89 is provided at its opposite ends with bayonet slots 95 for permitting insertion of the cover strip into the box-like member 93 beyond the bolt 92. A nut 96 is adjustable on the bolt 92 to force the box-like member 93 into gripping relation with the cover strip 94 and tab 8|.

The operating lever 49 controls the energization of the lamp 6! and renders the silencing circuit inoperative when the receiver is tuned to the desired station through the following circuit: The lead H! from the contact 9'! carried by the operating lever 49, is connected to the oathodes 91 of a pair of tubes 98 and 99 of the radio receiver through resistors El and R2 in parallel. These tubes may be the radio or intermediate frequency tubes or one of the audio-amplifier tubes. Resistors R3 and R4 are connected across the plate supply solace, the negative side of which is grounded, and the lead '59 and resistors R! and R2 are connected to a point between the resistors R3 and E i. An auxiliary switch M39 is connected to the lead 10 in shunt with resistor R 3. Interstage connections illl, W2 and I93 may be any usual or conventional coupling in which the grid leads I04 and I05 of the tubes 98 and 99 are grounded or otherwise connected to the negative voltage side of the resistor R4.

The circuit for the lamp 9| is completed from the ungrounded side of the secondary supply transformer 12 through wire ll, lamp 6! and wire 69 to contact 98, from contact 68 to the contact lug ll of the clip 14 and to the grounded strip 13 to which the clip '14 is resiliently secured. Lamps H16 and i9! (Fig. 4) may be mounted on the plate 1 behind the band indicator 24 by brackets Hi8 and N59 for the purpose of diffusely illuminating the dial plate is and color segments 25, 26 and 21.

During the tuning operation, i. e., during movement of the contacts 61 and 68 between the clips 14, the receiver is rendered silent by the biasing resistors Rl, R2, R3 and E i. These resistors are so proportioned in value that the grids of the tubes 98 and 99 automatically are biased to plate current cut-oi? so that no signal can be passed through said tubes. When the receiver is tuned to the desired station, indicated by a tab 8|, the contact 61 will be connected by the clip 14 to the grounded strip 13. The grounding of the lead 10 shunts out the resistor R4 and therefore decreases the bias on the grids of the tubes 98 and 99. Signals received by the tubes 98 and 99 will therefore be amplified and passed through the receiver in the normal operating manner.

In use, a number of tabs 8i, after being inscribed with the call letters of the most frequently selected broadcasting stations, are inserted into covers 89 and mounted on the clips 14, as previously described. The receiver is then tuned to one of the stations for which a tab has been prepared, and the clip M which carries a tab indicating that station is pressed on the annular strip 13 in alignment with the pointer 3'! and with the tab 8| and cover 80 overlying the translucent strip 94. The remaining clips are mounted in like manner at spaced distances along the annular strip i3. The clips having been thus arranged will thereafter energize the lamp and render the silencing circuit inoperative whenever the receiver is tuned to a station for which a tab has been prepared and afiised. Since the lever 46 is connected directly to the shaft 3!, it

will have a ratio of movement of substantial unity with respect to the tuning condenser and may be moved at such speed past an undesired station represented by one of the amxed tabs to the desired station, that the silencing circuit is not rendered inoperative. If, however, the lever 49 is moved more slowly only a slight clic will be heard as the contacts 61-98 engage a clip associated with an undesired intermediate station.

It will be seen from the above description that applicant has provided a radio receiver capable of both rapid and slow tuning; that he has provided simplified, inexpensive means which indicates by call letters as well as by frequency or wave length the proper tuning position of the receiver for the desired one of a number of broadcast stations, which means is readily replaceable and adjustable at the will of user; that he has provided tuning indicating means operable by said position-indicating means for indicating the tuned condition of the receiver; that he has provided automatically operable means for silencing the receiver during the tuning operation, which silencing means is rendered inoperative by the position-indicating means.

Changes may be made in the form, construction and arrangement of the parts without departing from the spirit of the invention or sacrificing any of its advantages, and the right is hereby reserved to make all such changes, as fairly fall within the scope of the following claims.

The invention is hereby claimed as follows:

1. In a tuning indicator for radio receivers and the like, a supporting plate having a plurality of openings and a portion separating said openings, a dial plate carrying indicia representative of broadcast frequencies in alignment with one of said openings, a plurality of spaced marking tabs, each carrying indicia representative of a selected broadcasting station, adapted to be detachably secured to said separating portion and overlying another of said openings, and means for selectively illuminating through said other opening the particular tab representing the station to which the receiver is tuned.

2. In a tuning indicator for radio receivers and the like, a tuning element, means for operating said tuning element, a pointer associated with said operating means, a dial plate having a scale associated with said pointer, a supporting plate having a guide portion extending parallel to said scale, said supporting plate having a pair of openings of which one is alined with said dial. plate, a plurality of marking devices each carrying indicia representative of a selected broadcasting station adapted to be detachably secured to said guide portion and extending over the other of said openings, and means for illuminating, through said openings, said dial plate and said marking devices.

3. In a tuning indicator for radio receivers and the like, a tuning element, cooperating and relatively movable scale and pointer elements, one of which is associated with said tuning element, indicating the tuning position of said tuning element, a supporting plate having a guide portion extending parallel to said scale element, a plurality of marking devices each comprising a tab carrying indicia representative of a selected broadcasting station, a transparent cover member for said tab, and a resilient clip having a portion for detachably securing said tab and cover member to said clip, and a portion for detachably securing said clip to the guide portion of said supporting plate.

4. In a tuning indicator for radio receivers and the like, a tuning element, cooperating and relatively movable scale and pointer elements, one of which is associated with said tuning element, indicating the tuning position of said tuning element, a supporting plate having a guide portion extending parallel to said scale element, a plurality of marking devices each comprising a tab carrying indicia representative of a selected broadcasting station, a transparent cover member for said tab, a resilient channel memher having a front and rear flange for receiving therebetween the guide portion of the supporting plate, said front flange having a resilient bent portion and forming the rear wall of a housing for receiving said tab and cover member, said member having a complementally bent portion engaging the bent portion of the front flange to be held thereby in detachable engagement with said channel member.

5. In a tuning indicator for radio receivers and the like, a tuning element, cooperating and relatively movable scale and pointer elements, one of which is associated with said tuning element, indicating the tuning position of said tuning element, a supporting plate having a guide portion extending parallel to said scale element, a plurality of marking devices each comprising a tab carrying indicia representative of a selected broadcasting station, a transparent cover member for said tab, and a resilient clip having a channel member for engaging the guide portion of the supporting plate and a clamping member adjustably secured to said channel memher for clamping said tab and cover member thereto.

In a tuning indicator for a radio receiver or the like, a dial plate carrying indicia representative of the broadcasting frequencies, a supporting plate for said dial plate having an opening therein for exposing said dial plate and a plurality of parallel annular slots concentric to said opening, a tuning element, a tuning shaft for operating said element, the free end of said shaft extending through said dial plate and said opening, a pointer on the free end of said shaft and co-operating with said dial plate to indicate the position of the tuning element, swingable operating means directly connected to said tuning shaft and extending through one of said annular slots to provide a high speed tuning adjusting means, and a plurality of marking devices each carrying indicia representative of selected broadcast stations secured to said supporting plate and extending into the other of said annular slots, said devices co-operating with said pointer to indicate the position to which the tuning element should be operated to tune the receiver to a desired station and to indicate the station to which the receiver is tuned.

7. In a tuning indicator for a radio receiver, a tuning element, means for adjusting said tuning element, a plurality of spaced marking devices, each of said devices indicating the position to which the tuning element should be moved to tune the receiver to a selected station, and electric signal means separate from the receiving circuits of a radio receiver, and cooperating switch means carried by said marking devices in said adjusting means for energizing said signal means to indicate that the receiver has been properly tuned to the desired one of said stations.

8. In a tuning indicator for a radio receiver, a tuning element, means for operating said tuning element, a dial assembly comprising a dial plate, a supporting plate, and a plurality of marking devices having metallic clips for securing said devices to said supporting plate, each of said marking devices carrying indicia representative of a selected broadcasting station, means for normally silencing the receiver, and means movable with said operating means and controlled by the resilient clips of said marking devices for rendering said silencing means inoperative when the receiver is tuned to a desired one of said selected stations.

means for controlling said grid biasing means and rendering said silencing means inoperative when the receiver is tuned to a desired station.

10. In a tuning indicator for a radio receiver, a tuning element, means for operating said tuning element, a plurality of spaced marking devices, each of said devices indicating the position to which the tuning element should be moved to tune the receiver to a selected station, luminous indicating means, and means controlled by said marking devices for energizing said luminous indicating means to indicate that selected stations.

11. In a tuning indicator for a radio receiver or the like, a movable pointer, a movable luminous indicator, fixed marking devices co-operating with said pointer and said luminous indicator, said marking devices having face portions adapted to be inscribed with the call letters of various broadilluminate the marking devices corresponding to to which the receiver is tuned.

tuning indicator for radio receivers and the like, a tuning element, means for operelement, a supporting plate having a guide portion extending parallel to the scale element, a plurality of marking devices each compriisng a tab carrying indicia representative of a selected broadcasting station and a resilient clip having a portion for frictionally engaging said tab and a provide a selective, luminously contrasting indication of the selected station.

WILLIAM J. SCHNELL.

CERTIFICATE OF CORRECTION. Patent N0. 2,182,572. December 5, 19 9.

WILLIAM J. SCHNELL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, first column, line 11-12, for "prosion" read provision; page 1;, second column, line 51, claimll, for the word "devices" read device; line 61, claim 12, for "compriisng" read comprising; and that the said Letters Patent should be readwith this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 16th day of January, A. D. 19m.

Henry Van Arsdale (Seal) -Acting Commissioner of Patents.

CERTIFICATE OF CORRECTION. Patent No. 2,182,572. Decemberfi, i9 9.

' WILLIAM J. SCHNELL. It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, first I column, line ll-l2, for "prosion'f read provision; page Lg, second column, line 51, claim 11, for the word "devices" read device; line 61, claim 12,

for "compriisng" read comprising; and that the said Letters Patent should.

be readwith this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 16th day of January, A. D. I9LLO.

Henry Van Arsdale,

(Seal) nActing Commissioner of Patents. 

